The Chargers lost cornerback Jason Verrett, an unrestricted free agent who signed a one-year, $3.6-million deal with San Francisco.
Taken 25th overall by the Chargers in the 2014 draft, Verrett became a Pro Bowler in his second season.
But injuries limited to him five games over the past three years. He missed all of 2018 after tearing his Achilles during a conditioning test before training camp opened.
The Chargers had publicly expressed interest in retaining Verrett immediately after the season.